Reversible cold cataracts of fish lenses have been reported in the literature. Preliminary studies in our laboratory have shown that some of the induced cold cataracts especially in the nucleus are irreversible. Furthermore, pressure will also develop nuclear cataracts and slicing fish lenses through the nucleus results in irreversible nuclear opacity. The proposed studies will investigate the conditions: temperature range, pressure range, oxidizing-reducing environment on the production of cataracts. The initial development of the cataracts will be followed by optical techniques such as light scattering in the I ion and I11 modes, birefringence measurements as well as spectral studies of possible dichroism. Furthermore, the molecular indicators such as size distribution of 2-crystallin aggregates, and the S-H/S-S ratios will be investigated.